Automatic hierarchical categorization of music by metadata

ABSTRACT

A method, performed by software executing on the processor of a portable music playback device, that automatically files tracks according to hierarchical structure of categories to organize tracks in a logical order. A user interface is utilized to change the hierarchy, view track names, and select tracks for playback or other operations.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is related to application Ser. No.______ entitled “System for Selecting and Playing Songs in a Playback Device with a Limited User Interface,” (Atty. Docket No. 17002-020800); and application Ser. No.______ entitled “Audioplayback Device with Power Savings Storage Access Mode,” (Atty. Docket No. 17002-022400), all filed Jan. 5, 2001, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] Today, portable consumer electronic devices are more powerful than ever. For example, small, portable music playback devices can store hundreds, even thousands, of compressed songs and can play back the songs at high quality. With the capacity for so many songs, a playback device can store many songs from different albums, artists, styles of music, etc.

[0003] Music jukeboxes implemented in software executed by a digital computer and portable MP3 and CD players both provide facilities for forming playlists. For example, the OOZIC player, distributed by the assignee of the present application, runs on a host PC and has a playlist feature that allows selection of tracks from the PC's hard disk to be included in the playlist.

[0004] As storage capacity increases and songs are compressed to shorter file lengths the number of songs that can be stored increases rapidly. Major problems facing the consumer are organizing and accessing the tracks.

[0005] Typically, portable devices have a user interface including a small screen and buttons. Using such a compact user interface to navigate and select among hundreds of songs is inefficient and often frustrating. The display screen can only show a few song titles at one time, and the limited controls make it difficult for a user to arbitrarily select, or move among, the songs.

[0006] The creation of playlists is one technique to organize the playing of songs. A set of songs can be included in a playlist which is given a name and stored. When the playlist is accessed, the set of songs can be played utilizing various formats such as sequential play or shuffle.

[0007] However, the creation of playlists itself becomes problematic as the number of songs increases, since the user often arbitrarily selects songs from a large number of tracks to form a playlist. This selection mechanism: can be fairly tedious; does not necessarily produce playlists that are of interest to the user over the course of time; may not remain up-to-date if new songs are added that logically fit into a previously created playlist (e.g. “Favorites by Band X” might become out of date if a new favorite by Band X is added after the playlist was created); and leads to “lost” songs that are not members of any playlist.

[0008] Accordingly, improved techniques for organizing and grouping tracks useful in a portable music player are needed.

SUMMARY OF THE INVENTION

[0009] According to one aspect of the present invention, a technique is provided for organizing tracks on a portable music player by automatically filing tracks in a hierarchical order based on attributes of the tracks.

[0010] According to another aspect of the invention, metadata is associated with each track that is used to automatically define the track's appropriate place in the hierarchy.

[0011] According to another aspect of the invention, the hierarchy is displayed on the portable music player so that a user can traverse the organizational hierarchy to find individual tracks or find playlists composed of logical groups of tracks.

[0012] According to another aspect of the invention, the hierarchy is derived by using metadata associated with the audio content that was obtained through any source of metadata (e.g. CDDB metadata, id3v2 metadata, other obtainable metadata) and subsequently stored with or alongside the file that stores the track.

[0013] According to another aspect of the invention, a file is formatted so that an unaltered track is stored as file data and information about the track is stored in file attribute files.

[0014] Other features and advantages of the invention will be apparent in view of the following detailed description and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic diagram of a tree structure for hierarchical filing of tracks;

[0016]FIG. 2 is a definition file that specifies the hierarchy depicted in FIG. 1;

[0017]FIG. 3 is a user's view of the hierarchy;

[0018]FIG. 4 is a schematic diagram of a user interface displaying the hierarchical category structure;

[0019]FIG. 5 is a diagram of a file format for storing filed data and file attributes;

[0020]FIG. 6 is a flow chart depicting steps for filing tracks according to the hierarchical tree structure;

[0021]FIG. 7 depicts a tree resulting from searching the tracks; and

[0022]FIG. 8 depicts a format for a user interface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A preferred embodiment of the invention will now be described in the context of a portable personal player that plays audio files stored in memory. The files may be in MP3, wav. or other digital formats.

[0024] In the presently described embodiment, users are able to see the tracks on their player in some organized fashion other than as a single list of tracks. As will be described in more detail below, in one embodiment tracks are sorted utilizing a tree structure having branches labeled according to types of metadata associated with the tracks

[0025] For example, a track recorded as “Golden Slumbers” by the Beatles that appears on their album “Hey Jude” might appear as a track under the album “Abbey Road” as well as a track under the list of tracks by the Beatles. It might appear as a track under the genre “Pop Rock” as well as “Songs from the 60's.” Furthermore, the organization can have more complex hierarchies. For example, the category of “Pop Rock” might contain subcategories “British Musicians,” “American Musicians” and “Other Musicians”. In all cases, the track is automatically filed into all appropriate locations without requiring user interaction.

[0026] In the currently defined embodiment, a tree structure is defined by a file having the following structure.

[0027] The first line of a TreeDef.inf file contains a version number:

[0028] V1.0

[0029] Each subsequent line (at least in v1.0) contains lines of the following format:

[0030] CATEGORY_NAME|TRACK_TYPE MASK|CATEGORY_STRUCTURE

[0031] CATEGORY_NAMEs are the top-level names of the branch under which tracks are sorted. They include things like “Album,” “Artist,” “Voice Tracks,” “All Tracks,” etc.

[0032] TRACKTYPE_MASKs tell which types of tracks are to be filed under this particular branch. The actual value is a hexadecimal numerical value (in ‘0X’ format, e.g. 0X01) generated by ORing the following flags together as appropriate: enum tTrackType { kTTNothing=0x00, kTTSong=0x01, kTTVoice=0x02, kTTBook=0x04, kTTMacro=0x08, kTTPlaylist=0x10 };

[0033] So, for example, the “Album” branch has a TRACK_TYPE_MASK of kTTSong, because only songs are filed under that branch, but the “All Tracks” branch has a TRACK_TYPE_MASK of (kTTSong|kTTVoice|kTTBook).

[0034] Other elements might be added to tTrackType (e.g. kTTVideo) as appropriate.

[0035] CATEGORY_STRUCTUREs tell how to file the songs based on their metadata information. The CATEGORY_STRUCTURE is a string of characters that tell, from left to right, the order of hierarchy. The characters come from the following enum constants: enum tFileTag { kFTNone=‘@’, kFTTrackType=‘T’, kFTTitle=‘N’, kFTAudioFile=‘F’, kFTArtist=‘M’, kFTAlbum=‘L’, kFTGenre=‘G’, kFTSource=‘S’, kFTYear=’Y’, kFTArtistCountry=’C’ };

[0036] Thus, a CATEGORY_STRUCTURE of LN tells to create a subcategory that is a list of Albums, each of which contains a list of Tracks.

[0037] In total, a line like:

[0038] Album|0×01|LN

[0039] Says to create a branch called “Album” which contains tracks of type kTTSong organized first by album name, and then by track name.

[0040] The following is an example of a tree definition file similar (though not identical) to the hierarchy presented in the Nomad Jukebox product (the ‘B’ before each FileTag was used to identify that these are basic tags so that we wouldn't run out of letters in the alphabet as we included more complex metadata—thus each group of two letters represents a level in the hierarchy): V1.0 Album|0x01|BLBN Artist|0x01|BMBN Genre|0x01|BGBN Voice Tracks|0x02|BSBGBN Playlists|0x10|BN Macros|0x08|BN All Tracks|0x07|BN

[0041]FIG. 1 depicts a hypothetical organization hierarchy. The tree shows how tracks might be listed (as leaves in the tree) after having been organized. Example values for nodes in the tree are shown as well. The same track may appear more than once as a leaf in the tree, as described above, if it fits into multiple categories (e.g. a song that appears on the Abbey Road branch would also appear in the Beatles branch). In the example shown, the first branch contains tracks organized by album. As shown in the example, this music collection contains three tracks from “Abbey Road” and three tracks from “Hits from the 60's”. The second branch contains tracks organized by artist, and sub organized by where the artist is from. Thus, a user browsing would first select the “Artists” branch and then choose between “British Artists” and “American Artists”. Finally, they would select the particular artist. In the third branch, all tracks are shown.

[0042] The tree definition file that would specify the hierarchy shown in FIG. 1 is shown in FIG. 2.

[0043] The first line identifies the version of the tree definition file.

[0044] The second line defines the “Albums” branch. The first part of the line, “Albums” defines the name of the branch. The second part, “0×01,” defines that all musical tracks should be categorized on this branch. The third part, “BLBN,” defines that the branch lists first the names of all albums (BL) and then tracks on those albums (BN).

[0045] The third line defines the “Artists” branch. The first part of the line “Artists” defines the name of the branch. The second part, “0X01, ” defines that all musical tracks should be categorized on this branch. The third part, “BCBMBN,” defines that the branch lists first the names of all countries where artists in this collection come from (BC) and under those items, the artists' names (BM), and then tracks by those artists (BN).

[0046]FIG. 3 shows what a user's view of this hierarchy might be if he/she were shown a fully expanded view of the 6-song tree. Notice that each song appears three times, once in each branch.

[0047] In consumer products the tree define file is not edited directly but through a user interface, one example of which is depicted in FIG. 4. An example of a user interface for viewing songs by category and editing the tree structure is depicted in FIG. 4.

[0048] An embodiment of the invention is utilized in the Nomad® Jukebox, manufactured by the assignee of the present invention, and described more fully in the copending application, filed on the same date as the present application, entitled “System for Selecting and Playing Songs in a Playback Device with a Limited User Interface,” (Attny. Docket No. 17002-020800).

[0049] In a preferred embodiment, metadata is associated with each track and includes such information as title, genre, artist name, type, etc. In the preferred embodiment, software stored in a portable player and executed by the onboard processor automatically files each track in the correct category utilizing the associated metadata and the tree define file. The program code can be stored in any computer readable medium including magnetic storage, CD ROM, optical media, or digital data encoded on an electromagnetic signal.

[0050] Thus, the user is automatically provided with a powerful and flexible tool for organizing and categorizing the tracks stored on the portable player.

[0051] If the tracks are formatted in MP3 format the metadata can be stored in ID3 tags included in the MP3 file. In one embodiment of the invention, the tracks are stored in alternate file format including file data and file attributes. The file data is the music track itself and the file attributes part of the file includes fields of arbitrary size which are used to store metadata characterizing the track stored as the file data. Again this metadata includes information about the track such as title, genre, artist name, type, etc.

[0052] There are several advantages to using the alternate file format. Metadata of types not easily included in an ID3 tag can be utilized. Further, the original track format is not changed, so that error correction data such as checksums are valid. Finally, any file format can be used (e.g. WAV, WMA, etc.) because the metadata is stored separately, and thus audio formats that have limited support for metadata can still be stored on the portable player in native format without transcoding. The formatted files are formed by software stored in the portable music player and executed by an on-board processor.

[0053] The metadata for each track is utilized to file each track, using the categories defined in the hierarchical structure as described above, without any input from the user.

[0054]FIG. 5 is a schematic diagram of the alternative file format including file data in the form of an MP3 track, and metadata fields for holding data indicating the name of the album the track is from, the name of the song, the genre of the song, and the type of track.

[0055] A particular embodiment of a file format will now be described. All tracks are created with some set of attributes as shown below: Definition of TrackInfo Data Field Field Offset Size Description Attribute Count  0 2 The number of attribute follow for the track Attr 1 type  2 2 Binary = 0, ASCII = 1 Attr 1 name len  4 2 Length of attribute name string Attr1 data len  6 4 Length of attribute data Attr1 Name 10 N Attribute name string Attr 1 Data 10 + N M Attribute data . . . . . . Attr N type Attr 1 name len Attr1 data len Attr1 Name Attr 1 Data Required Attributes Attribute Name Value(s) Remarks TITLE ASCII string Required By Jukebox CODEC “MP3”, “WMA”, “WAV” Required By Jukebox TRACK ID DWORD Set By Jukebox ALBUM ASCII string Optional ARTIST ASCII string Optional GENRE ASCII string Optional LENGTH In seconds Optional TRACK SIZE In bytes Optional TRACK NUM 1-n (track within album) Optional

[0056] These attributes can be subsequently changeable via a host application, running on a personal computer connected to the portable music player.

[0057]FIG. 6 shows a flow chart of an embodiment the process used to build the hierarchical database of tracks. It starts by iterating through each track, and, for each track, iterating through each branch to find if the track belongs on the branch, and, if so, where. In this case, the term track could refer to any content, e.g. a music track, a spoken word track, or even a video track.

[0058] Also, the hierarchical catalog of tracks can be used to form playlists in a structured manner. For example, if a user wants to hear Jazz and Blues the entire sub-categories can be selected to form one playlist.

[0059] An alternative hierarchical catalog generation technique will now be described. In this alternative embodiment, at system startup and as tracks are added or changed, the hierarchy is generated as an in-memory tree structure. Each track is added to the tree using the categories ALBUM, ARTIST and GENRE.

[0060] The following example shows the algorithm for adding a track. For clarity, only the attributes used by the tree are shown. TITLE “Free Falling” ALBUM “Full Moon Fever” ARTIST “Tom Petty” GENRE “Rock” TRACK NUM 1

[0061] The following function is executed to build the in-memory memory tree. Build Tree( ) For each track, Add Track To Category(Album, Track) Add Track To Category(Artist, Track) Add Track To Category(Genre,Track) End of Build Tree

[0062]FIG. 7 depicts a tree which could result from implementing Build Tree( ) function. Note that “Stardust” does not have any entries for Album or Artist. The host software running on a computer connected to the portable music player could be utilized to add missing attributes to the “Stardust” track and, optionally, edit the title attribute. The Build Tree( ) function would then reinsert this track in the correct location in the tree.

[0063]FIG. 8 is an embodiment of a user interface according to another embodiment of the invention. In this example the root node is labeled “My Configuration” and the Playlist category has been selected and the Playlist subcategory “Meddle” has been selected. Note that the types of Metadata, in this example, Track Name, Artist, Album, Tempo and Dance, are listed across the top of the screen, and the attribute values for each track are listed in a row across the screen. Various control buttons are displayed to the right of configuration window that facilitate quickly invoking selected processing on a selected track.

[0064] The invention has now been described with reference to the preferred embodiments. Alternatives and substitutions will now be apparent to persons of skill in the art. 

What is claimed is:
 1. A method, performed by a processor in a portable digital music player, for filing audio tracks stored on a computer readable media, with each audio track having metadata associated therewith including category value data for naming attributes of the track and type data indicating the type of track, said method comprising the acts of: reading a definition file that defines an ordered hierarchical tree structure, with the file including category names for naming the branch under which tracks are sorted, track type information specifying which type of tracks are to be sorted under the branch, and structure information defining how to file tracks based on associated metadata; for each track, iteratively determining, base on metadata describing the track, if the track belongs in the branch, and, for each branch in which the track belongs, traversing the branch to determine the appropriate location to file the track.
 2. The method of claim 1, where said act of searching further comprises the acts of: utilizing track type information to file only tracks of a specified type under a particular branch.
 3. The method of claim 1 further comprising the acts of: for each branch, utilizing category structure information to file tracks in a specified attribute order.
 4. The method of claim 1, where said portable digital music player includes a display screen and a user interface for interacting with the display, further comprising the acts of: displaying the categories and subcategories on the display in a hierarchical order; displaying all names of tracks associated with a category or sub-category when a user utilizes the interface to select a category or sub-category; utilizing the pointer to access and play a track when a user selects a track name through the user interface. and utilizing the pointer to access and play a collection of tracks within a category or subcategory when a user selects a category or subcategory through the user interface.
 5. A method, implemented by a processor in a portable digital music player, for associating metadata with audio tracks comprising the acts of: opening a formatted file for each track comprising a file data portion and a file attributes portion, with the file attributes portion including a plurality of fields corresponding to category types and file types; storing an unmodified audio track in the file data portion of the formatted file; and storing category type and file type information about the unmodified track in corresponding fields.
 6. A method, performed by a processor in a portable digital music player, for filing audio tracks, stored on a computer readable media, under categories in an in-memory tree structure, with each audio track having metadata associated therewith including category name data for naming, said method comprising the acts of: upon startup or when a track is added or changed, searching the metadata of each track; and for each track, automatically filing the track by category name under each selected category to form a hierarchical track filing scheme.
 7. The method of claim 6 further comprising the act of: selecting the categories to be the Album including the track, the title of the track, and the name of the artist that recorded the track.
 8. The method of claim 6, where said portable digital music player includes a display screen and a user interface for interacting with the display, further comprising the acts of: displaying the categories on the display in a hierarchical order; displaying all names of tracks associated with a category when a user utilizes the interface to select a category; accessing and playing a track when a user selects a track name through the user interface. and accessing and playing a collection of tracks within a category when a user selects a category through the user interface.
 9. A computer program product comprising: a computer readable medium having program code embodied therein for filing audio tracks stored on a computer readable media, with each audio track having metadata associated therewith including category value data for naming attributes of the track and type data indicating the type of track, said program code comprising: program code, executed by a processor, for reading a definition file that defines an ordered hierarchical tree structure, with the file including category names for naming the branch under which tracks are sorted, track type information specifying which type of tracks are to be sorted under the branch, and structure information defining how to file tracks based on associated metadata; program code, executed by a processor, for each track, for iteratively determining, base on metadata describing the track, if the track belongs in the branch, and, for each branch in which the track belongs, traversing the branch to determine the appropriate location to file the track.
 10. A computer program product comprising: a computer readable medium for having program code embodied therein for filing audio tracks, stored on a computer readable media, under categories in an in-memory tree structure, with each audio track having metadata associated therewith including category name data for naming, said program code comprising: program code, executed by a processor, upon startup or when a track is added or changed, for searching the metadata of each track; and program code, executed by a processor, for each track, for automatically filing the track by category name under each selected category to form a hierarchical track filing scheme. 